JP4238192B2 - Fireproof joint material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a fireproof joint material used at a part or all of a clearance of a through-hole provided in a fireproof compartment, or between a seismic isolation device of a building and a fireproof panel or at an end of the fireproof panel.

An expansion material for fire prevention has been used as a joint material between cables such as power cables and communication cables penetrating the fire protection compartment, piping such as air conditioning equipment, and the fire barrier. The expansion material for fire prevention expands by heating at the time of a fire to form an expansion layer, thereby closing a gap between through holes in the fire prevention compartment to prevent the spread of fire. For this reason, in the fireproof joint material made of the fireproof expansion material, it is required that the expansion layer is not easily deformed by the flame heat and can maintain a predetermined shape as long as possible, especially after the formation of the expansion layer. × 10 ⁴

  In the expansion material for fire protection, the expansion layer does not lose its shape due to the heat of the flame, and as a composition that maintains a predetermined shape for a long time, the base resin, the inorganic expansion agent and / or the organic expansion agent, and the shape stabilization resin A resin composition (for example, see Patent Document 1) in which a polycarbonate resin, a polyphenylene sulfide resin, a polyether ketone resin, a polyamide resin, a phenol resin, or the like is blended has been proposed. However, depending on the application, elasticity and flexibility were not sufficient and workability was poor.

  As a fireproof expansion material having excellent elasticity and flexibility, a method for producing polyurethane with fire resistance is also known (see, for example, Patent Document 2). This is characterized in that expansive graphite is blended in the polyol and polyisocyanate as a flame retardant and powdered casein is used as a shape stabilizer, but the shape stabilization is not sufficient. Furthermore, in this technique for producing polyurethane from a two-component reaction mixture of polyol and polyisocyanate, it is extremely difficult to blend a large amount of expansive graphite, and sufficient fire resistance performance cannot be obtained.

  In addition, a flexible fireproof rubber joint material made of rubber, expandable graphite, epoxy resin, and inorganic filler has been disclosed (for example, see Patent Document 3), and the brittleness and fire resistance, which have been problems in the past, have been improved. However, there is a problem that the epoxy resin blended for stabilizing the shape after expansion adheres to the inner wall of the kneading apparatus during kneading, and this removal is extremely difficult.

Furthermore, a composition in which boric acid is added to a flexible urethane foam blended with expansive graphite has been disclosed as an improvement in the stabilization of the shape after expansion (see, for example, Patent Document 4). When exposed, there was a problem of loss of elasticity due to hydrolysis.
JP 09-176498 A (2nd page: claims 1 to 5) Japanese Patent No. 2732435 (first page: claims 1-9, second claims 10-12) JP 2002-181262 A (page 2: claim 1) JP 2001-348476 A (2nd page: claims 1 to 8)

  In recent years, fire resistance performance is required not only to make the material itself difficult to burn but also to prevent the flame from turning to the back of the member, that is, fire prevention performance. The rubber component and organic component have the property of burning or melting by nature, so how long it can be prevented from being in such a state, or how to contain an inorganic component An important factor is whether the inorganic component can be retained for a long time without dropping off.

  The present invention solves the above-mentioned problems of the prior art, expands thermally in the event of a fire, closes the gap between the fire wall and the power cable to prevent the inflow of flames, and has sufficient shape retention. It is a fire joint material that ensures heat insulation, and provides a fire joint material that is excellent in long-term high-temperature durability.

  As a result of intensive studies, the present inventors have solved the above problem by using a composition containing a specific amount of thermally expandable graphite and a specific amount of epoxy resin in a flexible urethane foam as a fireproof joint material. The present inventors have found that the present invention can be accomplished and have completed the present invention.

  The joint material for fire prevention of the present invention can exhibit a fire prevention performance superior to that of the prior art. That is, in the event of a fire, the heat-expandable graphite forms an expanded layer and prevents the shape of the epoxy resin from losing its shape.

  The flexible urethane foam used in the present invention is a one-component type, and a flexible urethane foam obtained from an aqueous urethane prepolymer can be suitably used. As the aqueous urethane prepolymer, known products or commercially available products can be used.

  The fireproof joint material of the present invention is prepared by first adding water to thermally expandable graphite and epoxy resin to prepare a slurry, then adding an aqueous urethane prepolymer to the slurry, and continuing stirring and mixing until foaming starts, It is obtained by pouring into a mold having a predetermined shape and foaming, and curing at about 50 ° C. to evaporate the contained water. What is necessary is just to set a curing time suitably according to the magnitude | size and curing temperature of the foaming molding which is a joint material for fire prevention.

  The solid content in the slurry can be appropriately set according to the purpose and application of the final product, but is usually 20 to 90% by mass, preferably 50 to 70% by mass. When solid content is less than 20 mass%, there exists a possibility that the shape stability of the molded object obtained may fall. Moreover, when it exceeds 90 mass%, the viscosity of a slurry will rise and a desired fireproof joint material may not be obtained.

  Moreover, another additive can also be mix | blended with a slurry as needed. For example, surfactants, crosslinking agents, foam stabilizers, catalysts, foaming agents, flame retardants, stabilizers, ultraviolet absorbers, antioxidants, pigments, fillers, and the like. In the slurry, these components are blended simultaneously or sequentially, and then uniformly mixed with a known stirrer or the like.

The thermally expandable graphite used in the present invention is a powder obtained by treating natural graphite, pyrolytic graphite or the like with an inorganic acid such as sulfuric acid or nitric acid and a strong oxidizing agent such as concentrated nitric acid or permanganate. A crystalline compound maintaining a graphite layered structure. When these are exposed to a temperature of about 200 ° C. or higher, they thermally expand 100 times or more. There are various types of powders such as natural graphite and pyrolytic graphite in addition to the deoxidation treatment, as well as a neutralized treatment type.
The particle size of the thermally expandable graphite is preferably about 20 to 400 mesh. When the particle size is smaller than 400 mesh, the expansion coefficient of the thermally expandable graphite is small, and the obtained fireproof joint material may not be sufficiently thermally expanded in a fire, and when the particle size is larger than 20 mesh, the dispersibility may be deteriorated. The elasticity of the fireproof joint material may be reduced.

  The content of the heat-expandable graphite can be appropriately set depending on the type of flexible urethane foam, the desired expansion ratio, etc., but usually 10 to 100 parts by mass is preferably used with respect to 100 parts by mass of the flexible urethane foam. Is 20-80 parts by mass. If the content of the heat-expandable graphite is less than 10 parts by mass, the obtained fireproof joint material may not be sufficiently thermally expanded at the time of fire, and if it exceeds 100 parts by mass, the thermal expansion ratio is increased, but the obtained fireproof The hardness of the joint material tends to increase and physical properties such as strength tend to decrease.

  In the present invention, an epoxy resin is used as a shape stabilizer for preventing the deformation of the shape. As the epoxy resin used in the present invention, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyfunctional epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin and the like can be used. Is preferable in terms of excellent versatility. Moreover, in order to disperse | distribute an epoxy resin uniformly to water-based urethane foam, it is preferable to use with an emulsion or powder, and an emulsion is especially preferable from the surface of workability | operativity.

  The content of the epoxy resin is 20 to 200 parts by mass with respect to 100 parts by mass of the flexible urethane foam, and if it is less than 20 parts by mass, the shape stabilization performance of the obtained fireproof joint material is insufficient and 200 parts by mass is obtained. If it exceeds, the hardness of the obtained fireproof joint material becomes high and the flexibility is lowered, which is not preferable.

In this invention, in order to improve the flame retardance of the joint material for fire prevention more, an inorganic filler can be used. Examples of the inorganic filler include silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, magnesium oxide, iron oxide, magnesium hydroxide, aluminum hydroxide, zinc borate, sodium borate, calcium carbonate, magnesium carbonate, zinc carbonate, Barium carbonate, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, talc, clay, mica, bentonite, activated clay, sepiolite, glass fiber, glass beads, aluminum nitride, boron nitride, carbon black, graphite, etc. Two or more of these may be used in combination. Among these, aluminum hydroxide and magnesium hydroxide are preferable in that an endothermic reaction occurs due to water generated by a dehydration reaction during heating, and an increase in temperature is suppressed.
From the viewpoint of dispersibility, the average particle size of the filler is preferably 1 to 50 μm as measured by a laser diffraction method.

The content of the inorganic filler is preferably 10 to 50 parts by mass with respect to 100 parts by mass of the flexible urethane foam. When it exceeds 50 mass parts, the hardness of a foaming molding becomes high, flexibility is inferior, and workability may worsen.

The thermally expandable fire-resistant molded article of the present invention has an oxygen index of 40 or more. If it is less than 40, since the flame retardance at the time of a fire is inadequate and shape deformation prevention property is also inferior, it is unpreferable. Adjustment of the oxygen index is adjusted by the amount of expandable graphite and inorganic filler.

  The joint material for fire prevention of the present invention can be used in various fields that require properties such as elasticity, flexibility, thermal expansion, thermal insulation, fire resistance, vibration damping, and soundproofing, It can also be applied to a known method using the method, and may be used according to the method of use in each method. The use site is not particularly limited, and can be used widely in places where fire resistance is required.

  The joint material for fire prevention of this invention is used in order to block | close part or all of the clearance gap of the through-hole provided in the fire prevention division body. Moreover, it is used suitably also for the fireproof part of the seismic isolation device of a building. Specifically, the gap between the fire wall and the power cable, communication cable, pipe, etc. through the through-hole provided in the fire compartment such as the fire wall and floor slab is covered with the fire joint material of the present invention, or construction It can be used with a gasket molded in a shape that fits the part. In addition, this fireproof joint material is used between the seismic isolation device body and the fireproof panel that covers it, or at the end of the fireproof panel, and is attached with adhesive or adhesive, or fixed with bolts or nails, etc. Used.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, these Examples do not limit this invention. In addition, the part and% in the following description are based on a mass reference | standard.

  With the compounding amounts shown in Tables 1 and 2, water was added to a mixture of epoxy resin, thermally expandable graphite, and inorganic filler to prepare a slurry. Aqueous urethane prepolymer was added to the slurry, mixed with stirring, poured into a mold having dimensions of 12 cm × 12 cm × 17 cm, foam-molded, cured in an oven at 100 ° C. for 1 hour, and then demolded. The obtained foamed cured product was further cured in an oven at 50 ° C. for 2 days to evaporate the water, thereby obtaining a sponge-like molded product.

The materials used in the examples are as shown below.
(1) Aqueous urethane prepolymer: (Mitsui Chemicals, "EGH-401")
(2) Boric acid: (BORAX Co., Ltd.)
(3) Epoxy resin: bisphenol A type epoxy resin emulsion (JER Co., Ltd., “Epilet's 880SAW65”), bisphenol F type epoxy resin powder (JER Co., Ltd., “Epicoat 4010P”), polyfunctional epoxy resin emulsion (JER ( Corporation, "Epilettsu 6006W70")
(4) Thermally expandable graphite: (“SS-3” manufactured by Air Water Chemical Co., Ltd., expansion start temperature 260 ° C.)
(5) Inorganic filler: Aluminum hydroxide (“Hijilite H-42” manufactured by Showa Denko KK)

"Examples 1-4""Comparative Examples 1-4"
In the examples and comparative examples, the following characteristics were evaluated and summarized in Tables 1 and 2.
The measuring method of each characteristic is shown below.
Slurry state: The state of the slurry of the epoxy resin, the thermal expansion agent, the inorganic filler and water was examined. The flowable state was evaluated as ◯, and the non-flowable state was evaluated as x.
Surface hardness: Measured by reading the instruction of the hardness meter immediately after applying a C-type rubber hardness meter (manufactured by Kobunshi Keiki Co., Ltd.) to the foamed molded product.
Compression set: The foamed molded product was compressed by 10% in volume ratio, the volume after being left at 70 ° C. for 22 hours was measured, the ratio to the original volume was determined, and the recovery state of the volume was examined.
Expansion ratio: The expansion ratio after the foamed molded product was left in an atmosphere maintained at 300 ° C. for 0.5 hours was measured.
Shape retention: The foamed molded body was allowed to expand in an atmosphere maintained at 300 ° C. for 0.5 hour, and then the hardness of the expanded body was examined by finger touch. The case where the expanded body is hard and firm is indicated by ◎, the case where the shape can be maintained is indicated by ○, the case where the shape is managed somehow is indicated by Δ, and the case where the shape is not retained or melted is indicated by ×.
Durability: A test piece of 5 cm square was cut out from the foamed molded article, heat-treated in a gear oven at 100 ° C. for 5 days, and then left at room temperature for 1 day to observe the hydrolysis state of the sponge.
The case where the elasticity was not changed due to the finger touch was indicated as ◯, and the case where hydrolysis occurred and the elasticity was lost was indicated as X.

Claims (3)

It consists of 100 parts by mass of a flexible urethane foam obtained from an aqueous urethane prepolymer, 20 to 200 parts by mass of an epoxy resin, and 10 to 100 parts by mass of thermally expandable graphite, has an oxygen index of 50 or more, and 300 foam molded articles. A joint material for fire prevention having an expansion ratio of 3.9 to 4.5 after being left for 30 minutes in an atmosphere of ° C. The fireproof joint material according to claim 1, wherein an epoxy resin emulsion is used . After adding water to 10 to 100 parts by mass of thermally expandable graphite and 20 to 200 parts by mass of epoxy resin to prepare a slurry, 100 parts by mass of an aqueous urethane prepolymer is then added to the slurry, and stirring and mixing are performed until foaming starts. Next, a method for producing a fireproof joint material, which includes a step of injecting into a mold having a predetermined shape and foaming and evaporating the contained water .